When Jenny Burkholder, 51, first began feeling chest pain in 2019, she thought it was just the result of a yoga injury.
“I went into chaturanga, and I thought I had ripped the muscles around my sternum,” said Burkholder, who had previously survived early-stage breast cancer.
But after three months of physical therapy, her pain continued, and she finally visited her oncologist, who confirmed her worst fear.
“What I was feeling in my sternum was metastatic breast cancer,” she said.
Breast cancer is classified as metastatic, or stage 4, when it has spread outside of the breast and surrounding lymph nodes. Such a diagnosis was essentially a death sentence up until recently — in the early 1990s, just 18 percent of patients were still alive five years after they were diagnosed.
But while stage 4 breast cancer is still considered incurable, advancements in treatment are enabling a growing number of women like Burkholder to live with it.
Roughly 168,000 women in the U.S. were doing so as of 2020, according to a recent study from the National Cancer Institute.
That year’s figures marked a 31 percent increase from 2010, a 2021 study found. And the number of women living with advanced-stage breast cancer will continue to grow, another study predicted, increasing to 246,194 by 2030.
The growing ranks of women living with the disease reflect a marked improvement in survival rates. About 30 percent of women diagnosed with advanced-stage breast cancer lived with the disease for five years or more as of 2012-2018, according to the American Cancer Society.
And for younger patients, survival rates appear higher still: A 2018 study found that 56.5 percent of women between the ages of 20 and 39 survived five years past their diagnosis in 2010-2015, compared with 45.6 percent in 2005-2009.
The rising chance of survival “is entirely related to treatments,” said Joanne Mortimer, a medical oncologist at City of Hope’s main campus in Duarte, Calif.
“Years ago, our treatments were sort of a few chemotherapy regimens and some endocrine treatments,” Mortimer said. “Now, we have drugs that make endocrine treatment more effective, and it makes patients live longer.”
One of the reasons treatments for metastatic breast cancer have improved is that scientists know more about how the disease grows, mutates and moves throughout the body, according to health experts.
“We just have a better understanding of cancer biology these days,” Kelly McCann, an oncologist at the Jonsson Comprehensive Cancer Center at the University of California, Los Angeles, said.
“And a better understanding has led to better drug development and targeted therapies.”
One of the most significant breakthroughs in terms of understanding breast cancer came when scientists determined in 2013 that there are four main subtypes of the disease.
Those four major subtypes are HR+/HER2, or “luminal A”; HR-/HER2, or “triple negative”; HR+/HER2+, or “luminal B”; and HR-/HER2+, or “HER2-enriched”.
Some breast cancer subtypes are fueled by hormonal fluctuations in the body. And researchers now have a deeper understanding of how breast cancer cell receptors respond to those hormones — estrogen and progesterone — which has improved hormone and targeted therapies.
Advances in tumor sequencing also allow researchers and physicians to better see how a patient’s cancer cells are mutating and to potentially change their treatment approach based on those mutations.
Sabrina Wright-Hobart, 53, who was diagnosed with stage 2 breast cancer in 2006 and then stage 4 in 2021, can attest to just how far treatment has come.
To treat her rare form of metastatic breast cancer — mucinous breast carcinoma — she takes two medications called Letrozole and Ibrance.
Letrozole is an oral medication some breast cancer patients are prescribed to keep the disease from coming back. And Ibrance is a form of oral chemotherapy, which kills cancer cells, that received accelerated approval from the Food and Drug Administration (FDA) nearly a decade after Wright-Hobart was first diagnosed.
She also recently started to undergo a new type of blood test called a Signatera test.
Natera, the company that created the test, claims it has been used to detect a solid tumor recurrence two years earlier than it could via imaging.
“I believe if I would have had access to this test, I wouldn’t be stage 4,” said Wright-Hobart. “They would have caught my recurrence a lot sooner.”
Burkholder, meanwhile, has in the time after her diagnosis received more than one treatment for her cancer, which has spread to her spine.
And after a year of being on a medication called Enhertu, which received FDA approval last year, Burkholder told The Hill the cancer appears to have stopped growing.
Oncologists who spoke with The Hill stressed that people are living longer with metastatic breast cancer, and in some cases living better, than they have in the past thanks to less invasive and more personalized treatments.
Anne Keane, a 43-year-old Massachusetts resident, has completed two Boston Marathons and signed up for a third since being diagnosed with metastatic breast cancer at age 36.
Like Burkholder, Keane felt a pain in her sternum while exercising and, thinking it had something to do with her heart, decided to see her doctor about it.
At first, doctors also thought the pain was related to her heart. But an X-ray and some tests showed that Keane actually had stage 4 breast cancer that had spread to her liver, lymph nodes and bones.
Keane thinks she is lucky not just because she has lived with the disease past the five-year mark, but also because her treatment hasn’t impacted her too harshly.
Her regimen includes taking Letrozole daily and taking Herceptin and a targeted therapy medication called Pertuzumab intravenously in her doctor’s office once a week.
Since starting her treatment, Keane has suffered from brain fog, memory spots, joint pain and a sort of permanent menopause for the last seven years.
“The side effects are really not bad,” Keane said. “I mean, I actively trained for a marathon through it.” She added that after her intravenous treatments, she feels a little bit more tired.
But while some may assume that her condition is akin to living with a chronic illness, she takes issue with that description.
“There is nothing guaranteed with this,” she said. “I joke that I’m a unicorn because it’s so rare and I’m so lucky and so blessed that this is my prognosis. But that is not the case for so, so, so many others.”
While overall survival rates have improved, the odds remain more stark for some patients.
Where cancer has spread plays a role in determining those odds. Women have a greater chance of surviving stage 4 breast cancer if the disease has only spread to the bones and the lowest if it has reached the brain, according to one 2019 study.
Outcomes also vary notably with different breast cancer subtypes.
There is about a 20 percent five-year survival rate for women diagnosed with a rare subtype called inflammatory breast cancer, for example, according to data from the American Cancer Society.
Those diagnosed with the rare and aggressive triple-negative breast cancer subtype face even lower survival rates after being diagnosed with a stage 4 case: Only about 12 percent make it to the five-year mark.
Black women are twice as likely to be diagnosed with triple-negative breast cancer as white women, according to the American Cancer Society. And they are also 30 percent more likely to die from triple-negative tumors because of lower rates of surgery and chemotherapy.
Black women have the lowest five-year survival rate for metastatic breast cancer of any racial or ethnic group regardless of the type of breast cancer they are diagnosed with, at about 24 percent, according to the Centers for Disease Control and Prevention (CDC).
That is about 16 percentage points lower than the figure for Asian women, who have the highest five-year survival rate.
Outcomes also worsen with age, according to data from the CDC. Five-year survival rates start to decline slightly past the age of 45, with women aged 75 and up having about a 20 percent five-year survival rate compared with a rate of more than 40 percent for women younger than 45.
“So many people are living with metastatic disease and for longer,” said Wright-Hobart. “We still have a lot of work to do, but we’ve come a long way.”